166
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 252
- Proper Divisor Sum (Aliquot Sum)
- 86
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 82
- Möbius Function
- 1
- Radical
- 166
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 111
- Smith Number
- yes
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Names
- German
- einshundertsechsundsechzig· ordinal: einshundertsechsundsechzigste
- English
- one hundred sixty-six· ordinal: one hundred sixty-sixth
- Spanish
- ciento sesenta y seis· ordinal: 166º
- French
- cent soixante-six· ordinal: cent soixante-sixième
- Italian
- centosessantasei· ordinal: 166º
- Latin
- centum sexaginta sex· ordinal: 166.
- Portuguese
- cento e sessenta e seis· ordinal: 166º
Appears in sequences
- Number of binary partitions: number of partitions of 2n into powers of 2.at n=15A000123
- Positive zeros of Bessel function of order 0 rounded to nearest integer.at n=52A000134
- Number of 3-dimensional polyominoes (or polycubes) with n cells.at n=5A000162
- Number of steps to reach 1 in sequence A000546.at n=20A000547
- Number of alkyls X^{II} C_n H_{2n+1} Y with n carbon atoms.at n=6A000645
- Semiprimes (or biprimes): products of two primes.at n=54A001358
- The partition function G(n,3).at n=6A001680
- 2 together with primes multiplied by 2.at n=23A001747
- Primes together with primes multiplied by 2.at n=60A001751
- Expansion of 1/((1+x)*(1-x)^6).at n=5A001753
- Sorting numbers: number of comparisons for merge insertion sort of n elements.at n=40A001768
- Related to graded partially ordered sets.at n=3A001827
- Number of partitions with no even part repeated; partitions of n in which no parts are multiples of 4.at n=17A001935
- a(n) = floor((n+2/3)*(5+sqrt(13))/2); v-pile positions in the 3-Wythoff game.at n=38A001960
- v-pile positions of the 4-Wythoff game with i=3.at n=31A001968
- Number of partitions of floor(7n/2)-1 into n nonnegative integers each no greater than 7.at n=7A001980
- Number of partitions of n into parts 2, 3, 4, 5, 6, 7.at n=27A001996
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k*x is 0.at n=73A002158
- Values taken by reduced totient function psi(n).at n=61A002174
- Values taken by totient function phi(m) (A000010).at n=60A002202